Digester Additives

• In wood/agriculture residue pulping, wood chips are cooked in a digester at an elevated temperature in white liquor. The white liquor is essentially a caustic solution containing poly-sulphides which penetrate into the capillaries of the wood to dissolve the lignin in the wood chips.
• The digester additives are effective in reducing both the Kappa number and percentage of rejects during the cooking of wood chip. The use of the digester additives results in the uniform cooking of the wood chips in the digester; improve good yields of wood pulp and decreases rejects. In addition, surfactant mixtures provide wetting properties that allow quick and more uniform penetration of the cooking liquor into the capillaries of wood chips, thus reducing the rejects as well as reducing the cooking time.
• Reduction in white liquor charge / Active Alkali reduction
• Reduced Rejects/Yield gain
• Increased unbleached brightness
• Reduced bleaching chemicals
• Reduced soda loss

Wash Aids

Cubane Silicone based wash aids reduce organic and inorganic carryover, thereby reducing wash losses, and losses resulting from foam generation. An effective brown stock washing system with the use of an effective wash aid will recover a considerable amount of spent cooking chemical with minimal operating and capital expenses.

The benefits derived from efficient washing include:

• Less Kraft mill salt cake makeup needed in the liquor system at the furnace.
• Brighter pulp from the brown stock washer
• Good Foam control in the washers improves stock drainage by removing entrained air. This increases the capacity of the washers.
• More solids are removed into the liquor phase because of better washing rather than increased quantities of wash water. This means higher heating values for the black liquor going to the evaporators and recovery boilers.
• As more organic material is removed with the use an effective wash aid, the potential pitch problems in the pulp and paper mill are decreased.
• BOD and color loading of pulp and paper mill effluent is reduced by better washing in the pulp mill.

Pitch Control

Our product is based on micro encapsulation of the colloidal pitch particles and also the use of dispersant to obtain synergy. This non-ionic polymer adsorbs onto the colloidal material, enhancing stability and modifying the contaminant surface to reduce adhesion.

Benefits:

• Eliminates/reduces pitch deposition
• Eliminates/reduces pitch-related dirt
• Improved pulp quality
• Decreased downtime for cleaning

Scale Control

(Digester, Wash plant, Bleach Plant and Evaporators & vacuum pumps)

Most of the calcium entering the digester, bleach plant, evaporator comes into the mill with the fibre source itself, Calcium precipitates as calcium carbonate in the digester. The calcium then dissolves once the pH drops below 7.

The scaling process is controlled by four critical parameters:

• Cation concentration (e.g., calcium)
• Anion concentration (e.g., carbonate)
• pH
• Temperature

Most effective means for controlling scale deposits are based on three basic chemical mechanisms:

• Control of the rate of precipitation and of crystal growth.
• Control of particle agglomeration and nature of scale deposit by affecting particle-to particle attractive forces.
• Crystal modification.

Lime mud dewatering

Lime mud dewatering aids are used to improve removal of water or to increase the dryness at the filter and to increase the fuel efficiency of the lime kiln. In the process it is also employed to help lower total re-duced sulphur (TRS) emissions which are an environmental concern. Dewatering Aids work via two primary mechanisms - Increased de-watering and increased washing. Generally, 20-40%of the material going into the precoat filter vat is mud solids. The remaining 60- 80% consists of three types of water.

• Free water
• Sorbed Water
• Water of crystallization

Dewatering Aids have both hydrophobic and hydrophilic functional groups. These molecules free Sorbed water from the surface of lime mud particles. The hydrophilic binding group attaches the dewatering aid molecule to the surface of the calcite particles which are also hydrophilic. The opposite side of the dewatering aid molecule, the hydrophobic side, then displaces and repels the Sorbed water on the surface of the lime mud calcite particles. The sodium content of the mud directly impacts the size of the reburnt lime particle formed. Too much sodium can contribute to the formation of balls and rings and cause operational problems in the kiln.